CI Total 4
21. Vidhur is thinking of a three digit number.
The first digit is not zero.
The three digit number is exactly divisible by 5.
How many numbers fit the criteria of the number that Vidhur is thinking of?
You must show all of your working.

Where’s the graph too show me?

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.